The present invention relates to an ad-hoc network of the kind comprising a plurality of telephones at least one of the plurality of telephones is a mobile repeater telephone for establishing a first telephone connection line between a first caller telephone and a first receiver telephone in the ad-hoc network, which at least one mobile repeater telephone is of the kind having at least one transmitter, at least one receiver, a processor, and at least one repeater for repeating a signal received and/or transmitted by the at least one mobile repeater telephone for establishing the at least one telephone connection line, wherein the at least one transmitter, the at least one receiver, and the at least one repeater simultaneously allow establishing at least one second telephone connection line between at least one second caller telephone and at least one second receiver telephone different from the first caller telephone and the first receiver telephone, respectively, and at least a subset of all the mobile repeater telephones in the ad-hoc network having its own unique code and at least a subset of all the unique codes of the mobile repeater telephones in the ad-hoc network being known to at least a subset of all mobile repeater telephones in the ad-hoc network.
In the following, the term “cellular telephone” is to be understood as a telephone that when calling or being called connects to or is connected to a cellular telephone antenna tower (base station antenna) and then further to the receiver telephone.
To call from one cellular telephone to another is expensive even though the cellular telephone users are very close to each other. This depends on that the signal between the cellular telephones must pass the cellular telephone antenna towers and use a cellular telephone operator's cellular telephone system. Apart from being expensive the necessity to use the cellular telephone antenna tower also has several other drawbacks. If e.g. the cellular telephone antenna tower breaks or the current supply to the cellular telephone antenna tower breaks the use of cellular telephones in the area surrounding that cellular telephone antenna tower is not possible outside the range of neighboring cellular telephone antenna towers. In sparsely populated areas where there are no cellular telephone antenna towers at all, the person to call can be very close and still not reachable by the cellular telephone. The same is true in rural areas where the cellular telephone antenna towers are far from each other. If the cellular telephone user walks down in a depression in the terrain it can be enough to lose the contact to the cellular telephone antenna tower and even though the other cellular telephone user is close the connection is lost. Finally in a catastrophe area, like after an earthquake or another natural disaster, all the cellular telephone antenna towers may be destroyed. One way to communicate is then over a walkie-talkie system. Over such a system the caller cannot choose destination and everybody will be interrupted in their work to listen to the message and loose time in their lifesaving efforts.
US patent application with application no. 2003/0142638A1 discloses mobile phones, which form an ad-hoc network and are also able to connect to a cellular tower and a cellular network. The mobile phones each have one set of connecting units consisting of a receiver, a repeater and a transmitter to receive and transmit telephone calls between other mobile phones of the ad-hoc network. The set of connecting units of a first mobile phone jumps from connecting a first call, to connecting the second call, to connecting the third call and so on until the set of connecting units has connected all telephone calls which uses the first mobile phone as a connecting node. Then the set of connecting units will again connect the first call, continue with the second call and so on. This jumping from one call to another means that the connecting unit must switch from one call to another which takes time. A land mobile satellite system with portable communication terminals (mobile telephone) with two transceivers is known from EP1179896. One of the transceivers is used for connecting to a conventional cellular mobile system via an antenna of the conventional cellular mobile system while the other transceiver is used to connect through mobile repeater stations to another portable communication terminal. The portable communication terminals are only used for telephone conversation and similar data traffic and the two transceivers do not comprise repeaters to increase the signal-to-noise ratio and thus the portable communication terminals cannot be used as repeaters for connecting other portable communication terminals. One portable communication terminal cannot communicate directly with another portable communication terminal. The communication between two communication terminals must pass through at least one mobile repeater station. The mobile repeater stations according to EP1179896 contain many transceivers, where each transceiver comprises a receiver, a repeater and a transmitter. However, the mobile repeater stations cannot be used as telephones. Each mobile repeater station is described in EP1179896 to need means for generating and storing electric power, such as a generator, which will be driven by a gasoline engine, or a fuel cell, or solar batteries to assure enough power supply to the mobile repeater station. This is due to the fact that the system depends on land-satellite contact which is highly energy demanding.
European patent application no. EP1826964A1 discloses a system where there is an ad-hoc network of mobile terminal devices, only. The mobile terminal devices in this network can be in any of three states. If two users talk to each other their respective mobile terminal devices are in a first state. If these two first mobile terminal devices are too far from each other to communicate directly with each other there are one or more second mobile terminal devices between the two first mobile terminal devices that are in a second or third state and act as intermediaries between the first two mobile terminal devices. There is a problem when the users of one of the intermediary second mobile terminal devices tries to make a call. Then the user's mobile terminal device will go over to the first state and not be able to connect a telephone call between the two first mobile terminal devices. The network has to find a new route between the two first mobile terminal devices. In an area where the mobile terminal devices are far from each other and there is no alternative connection route, the connection between the two first mobile terminal devices will break. The network will not be used efficiently.
In the system disclosed in US patent application no. US2007/0253376 every cellular telephone has two transceivers or two pairs of one transmitter and one receiver. The one pair of transmitter and receiver communicates with a regular cellular telephone network via the cellular telephone antenna towers, while the other pair of transmitter and receiver communicates with an ad-hoc network. A cellular telephone that connects to other cellular telephones in the ad-hoc network is still able to make a telephone call using the regular cellular telephone network, but the solution disclosed in US2007/0253376 does not solve the problem of at the same time both acting as an intermediary between other cellular telephones and calling another cellular telephone in e.g. a catastrophe area where there are no cellular telephone antenna towers at all.
Thus there is a need for an ad-hoc network of mobile phones which depend on only mobile phones to function. Furthermore there is a need for an ad-hoc network of mobile phones which may have the capacity to handle a large number of simultaneous conversations or heavy data traffic, with a minimum of delay in the transmissions between phones in the ad-hoc network and which is less vulnerable to local malfunctions of telephones in the ad-hoc network than previously known systems.